Communication device and radio frequency circuit

Abstract

A communication device and a radio frequency circuit are provided. The communication device includes an antenna element, a transceiver, and the radio frequency circuit. The radio frequency circuit includes a substrate, a first conducting wire, a second conducting wire, and four transmission lines. The four transmission lines are respectively connected to two ends of the first conducting wire and two ends of the second conducting wire to form an input part, an output part, a coupling part, and an isolation part, respectively. The first conducting wire and the second conducting wire are separate from each other and coupled to each other, and each of a width of the first conducting wire and a width of the second conducting wire is not equal to a width of any one of the four transmission lines.

What is claimed is: 
     
       1. A communication device for operating in an operating frequency band, the communication device comprising:
 an antenna element; 
 a transceiver electrically connected to the antenna element, the transceiver having a transmitting end and a feedback receiving end; and 
 a radio frequency circuit electrically connected between the antenna element and the transceiver, the radio frequency circuit including:
 a substrate; 
 a first conducting wire disposed on a first surface of the substrate; 
 a second conducting wire disposed on the first surface and arranged corresponding to the first conducting wire; and 
 four transmission lines disposed on the first surface, wherein two of the four transmission lines are respectively connected to two ends of the first conducting wire to form an input part and an output part, and another two of the four transmission lines are respectively connected to two ends of the second conducting wire to form a coupling part and an isolation part; wherein the input part is arranged corresponding to the coupling part, and the output part is arranged corresponding to the isolation part; wherein the input part is electrically connected to the transmitting end, the output part is electrically connected to the antenna element, the coupling part is electrically connected to the feedback receiving end, and the isolation part is connected to a ground potential; 
 
 wherein the first conducting wire and the second conducting wire are separate from each other and coupling to each other, and each of a width of the first conducting wire and a width of the second conducting wire is not equal to a width of any one of the four transmission lines. 
 
     
     
       2. The communication device according to  claim 1 , wherein each of the four transmission lines has an adaption part at one end of each of the four transmission lines that is connected to the first conducting wire or the second conducting wire, and an edge profile of the adaption part is a quarter arc having a radius defined by the width of the transmission line. 
     
     
       3. The communication device according to  claim 1 , wherein the first conducting wire has at least one first branch and at least one second branch that are staggered with each other, and the second conducting wire has at least one third branch and at least one fourth branch that are staggered with each other; wherein each of a width of the at least one first branch and a width of the at least one third branch is less than the width of any one of the four transmission lines, and each of a width of the at least one second branch and a width of the at least one fourth branch is greater than the width of any one of the four transmission lines. 
     
     
       4. The communication device according to  claim 3 , wherein, when the first conducting wire is arranged corresponding to the second conducting wire, the at least one first branch of the first conducting wire corresponds to the at least one fourth branch of the second conducting wire, and the at least one second branch of the first conducting wire corresponds to the at least one third branch of the second conducting wire. 
     
     
       5. The communication device according to  claim 4 , wherein a first edge is defined by an extension of a side of the at least one second branch of the first conducting wire, a second edge is defined by an extension of a side of the at least one fourth branch of the second conducting wire, and the first edge and the second edge coincide with each other. 
     
     
       6. The communication device according to  claim 4 , wherein a first edge is defined by an extension of a side of the at least one second branch of the first conducting wire, a second edge is defined by an extension of a side of the at least one fourth branch of the second conducting wire, a distance between the first edge and the at least one third branch is less than the width of the at least one fourth branch, and a distance between the second edge and the at least one first branch is less than the width of the at least one second branch. 
     
     
       7. The communication device according to  claim 3 , wherein the operating frequency band has a minimum operating frequency, and a first wavelength is obtained according to an initial wavelength of the minimum operating frequency in vacuum and a dielectric coefficient of the substrate; wherein a first edge is defined by an extension of a side of the at least one second branch of the first conducting wire, a second edge is defined by an extension of a side of the at least one fourth branch of the second conducting wire, there is a distance between the first edge and the second edge, and the distance is between 1/200 times and 1/4 times of the first wavelength. 
     
     
       8. The communication device according to  claim 3 , wherein, when the first conducting wire is arranged corresponding to the second conducting wire, the at least one first branch corresponds to the at least one third branch, and the at least one second branch corresponds to the at least one fourth branch. 
     
     
       9. The communication device according to  claim 3 , wherein the radio frequency circuit further includes a metal layer disposed on a second surface of the substrate, and the second surface is opposite to the first surface; wherein the metal layer has a plurality of first annular slots that are arranged linearly thereon, projections of the plurality of the first annular slots onto the substrate are close to or overlap with a projection of the at least one first branch, a projection of the at least one second branch, a projection of the at least one third branch, and a projection of the at least one fourth branch onto the substrate. 
     
     
       10. The communication device according to  claim 9 , wherein the metal layer has a plurality of first parts and a second part, and the plurality of first annular slots respectively surround the plurality of first parts; wherein each of the plurality of first parts has one of a plurality of first conductive parts and a first connection part formed therein, the first conductive part is arranged in an area that is surrounded by a corresponding one of the plurality of first annular slots, and the first connection part is connected between the one of the first conductive parts and the second part. 
     
     
       11. The communication device according to  claim 10 , wherein each of the plurality of first conductive parts has a second annular slot formed therein, and the second annular slot surrounds a part of the one of the first conductive parts; wherein a second conductive part and a second connection part are formed within the part of the one of the first conductive parts, and the second connection part is connected between the first conductive part and the second conductive part. 
     
     
       12. A radio frequency circuit, comprising:
 a substrate; 
 a first conducting wire disposed on a first surface of the substrate; 
 a second conducting wire disposed on the first surface and arranged corresponding to the first conducting wire; and 
 four transmission lines, wherein two of the four transmission lines are respectively connected to two ends of the first conducting wire to form an input part and an output part, and another two of the four transmission lines are respectively connected to two ends of the second conducting wire to form a coupling part and an isolation part, wherein the input part is arranged corresponding to the coupling part, the output part is arranged corresponding to the isolation part, and the isolation part is connected to a ground potential; 
 wherein the first conducting wire and the second conducting wire are separate from each other and coupling to each other, and each of a width of the first conducting wire and a width of the second conducting wire is not equal to a width of any one of the four transmission lines. 
 
     
     
       13. The radio frequency circuit according to  claim 12 , wherein each of the four transmission lines has an adaption part at one end of each of the four transmission lines that is connected to the first conducting wire or the second conducting wire, and an edge profile of the adaption part is a quarter arc having a radius defined by the width of the transmission line. 
     
     
       14. The radio frequency circuit according to  claim 12 , wherein the first conducting wire has at least one first branch and at least one second branch that are staggered with each other, and the second conducting wire has at least one third branch and at least one fourth branch that are staggered with each other; wherein each of a width of the at least one first branch and a width of the at least one third branch is less than the width of any one of the four transmission lines, and each of a width of the at least one second branch and a width of the at least one fourth branch is greater than the width of any one of the four transmission lines. 
     
     
       15. The radio frequency circuit according to  claim 14 , further comprising:
 a metal layer disposed on a second surface of the substrate, the second surface being opposite to the first surface; 
 wherein the metal layer has a plurality of first annular slots that are arranged linearly thereon, projections of the plurality of the first annular slots onto the substrate are close to or overlap with a projection of the at least one first branch, a projection of the at least one second branch, a projection of the at least one third branch, and a projection of the at least one fourth branch onto the substrate. 
 
     
     
       16. The radio frequency circuit according to  claim 15 , wherein the metal layer has a plurality of first parts and a second part, and the plurality of first annular slots respectively surround the plurality of first parts; wherein each of the plurality of first parts has a first conductive part and a first connection part formed therein, the first conductive part is arranged in an area that is surrounded by a corresponding one of the plurality of first annular slots, and the first connection part is connected between the first conductive part and the second part.